Microwave accelerated Castagnoli-Cushman reaction: Synthesis of novel 6,7,8,9-tetrahydropyrido[3′,2′:4,5]pyrrolo[1,2-a]pyrazines

The Castagnoli-Cushman reaction of various azaindole dicarboxylic acids with imines using acetic anhydride as a dehydrating agent was significantly accelerated by microwave irradiation. The reaction conditions offer a convenient preparation of novel 6,7,8,9-tetrahydropyrido[3',2':4,5]pyrrolo[1,2-a]pyrazines in moderate to good yields with good trans stereoselectivity. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

The Castagnoli-Cushman reaction of various azaindole dicarboxylic acids with imines using acetic anhydride as a dehydrating agent was significantly accelerated by microwave irradiation, leading to the convenient preparation of novel compounds with good yields and stereoselectivity.